What it does is cancels the crosstalk electroniclly gives you a larger soundstage and if setup properly , will make the speakers disappear ( only works in 2 channel setup ) .
The New Sunfire Pre's come with the feature also .
I run SDA on one system and sonic hologram on 2 systems in my house and my car system also .
I like the feature .
Also , SH can vary in the Pre's , I like the SH in the CT 7 ( a newer pre designed by Bob himself ) . The C 1 , 11 and 16 are better because of no floor noise .
Again that C 1 and C 11 is unreal for a turntable , 2 phono cart. inputs ( Moving magnet and moving coil , with 3 settings for moving magnet )